1. Field of the Invention
This invention relates to a liquid crystal pixel interpolating mechanism in a liquid crystal photo printer for projecting an image, which is displayed on a liquid crystal panel, through a projecting lens onto a photosensitive material and thereby printing the image on the photosensitive material.
2. Description of the Prior Art
Liquid crystal photo printers have heretofore been proposed. With the liquid crystal photo printers, image signals having been obtained by reading out images, which have been recorded in frames on negative film, with a scanner are stored in an image memory. An image signal representing an image of a frame, which image is to be printed, is read from the image memory and utilized for displaying the image on a liquid crystal panel. Also, the image displayed on the liquid crystal panel is projected onto photographic paper, and the photographic paper having thus been exposed image-wise is processed to form a print.
Also, index prints are often formed by printing the images of respective frames on negative film as printed images, which have reduced image sizes and are arrayed in a matrix-like form, such that it can be investigated easily what photographs have been taken on a roll of developed negative film. With the liquid crystal photo printers described above, in cases where the index prints are to be formed, image signals representing images having been recorded in several frames can be read from the image memory and utilized for displaying the images of the several frames on the liquid crystal panel, and the displayed images of the several frames can be projected onto the photosensitive material (the photographic paper). The photosensitive material having thus been exposed image-wise can then be processed to form an index print.
Also, with the liquid crystal photo printers described above, in cases where a print of a predetermined enlarged image size is to be formed, the entire area of the image of the frame to be printed can be displayed on the liquid crystal panel, the displayed image can be projected onto and formed on the photographic paper with a predetermined image size enlargement scale.
As described above, an image displayed on a liquid crystal panel, which is constituted of a plurality of pixels arrayed in two-dimensional directions and at predetermined pitch dimensions, may be projected through a projecting lens onto photographic paper with an image size enlargement scale, and an image having an enlarged image size may be printed on the photographic paper. However, as illustrated in FIG. 8, each pixel of the liquid crystal panel is constituted of a window W and an electrode area E. Therefore, in cases where a plurality of exposure dots D, D, . . . , which correspond to the pixels arrayed in, for example, a zigzag lattice-like form and at predetermined pitch dimensions, are formed on the photographic paper and in the form shown in FIG. 9, a projected image area corresponding to the window W becomes blackened, but a projected image area corresponding to the electrode area E remains white as an un-blackened area. Accordingly, the problems occur in that the maximum blackened image density cannot be kept high and a printed image having a high contrast cannot be obtained.
In order to eliminate the problems described above, a pixel shifting technique has been proposed in, for example, Japanese Unexamined Patent Publication No. 8(1996)-227108. With the pixel shifting technique, a liquid crystal panel is firstly located at a reference position, and an image displayed on the liquid crystal panel is projected onto a photosensitive material. Thereafter, the liquid crystal panel is displaced at least one time in a direction, which is normal to the exposure optical axis, such that the pixels of the liquid crystal panel may not overlap each other, and the exposure operation is again performed at the displaced position. In this manner, the un-blackened areas, which were formed on the photosensitive material in the first exposure operation, are blackened. Also, a technique has heretofore been employed, wherein the un-blackened areas are eliminated by the utilization of a polarizing plate formed from lithium niobate, or the like.
However, the pixel shifting technique described above has the drawbacks in that, since the liquid crystal panel is moved by the utilization of a piezo-electric device, the constitution cannot be kept simple. Also, the technique for eliminating the un-blackened areas by the utilization of the polarizing plate has the problems in that the polarizing plate is expensive and the exposure operation is apt to be adversely affected by dust, or the like.
The primary object of the present invention is to provide a liquid crystal pixel interpolating mechanism in a liquid crystal photo printer, wherein a pixel shifting operation is capable of being performed with a simple constitution.
Another object of the present invention is to provide a liquid crystal pixel interpolating mechanism in a liquid crystal photo printer, wherein a pixel shifting operation is capable of being performed accurately.
The present invention provides a liquid crystal pixel interpolating mechanism in a liquid crystal photo printer, wherein an image displayed on a liquid crystal panel, which is constituted of a plurality of pixels arrayed in two-dimensional directions and at predetermined pitch dimensions, is projected through a projecting lens onto a photosensitive material and printed on the photosensitive material, the mechanism comprising:
i) a liquid crystal panel support member, which is supported with resilient members, and
ii) pushing means for pushing the liquid crystal panel support member.
In the liquid crystal pixel interpolating mechanism in a liquid crystal photo printer in accordance with the present invention, the pushing means may be constituted of a set-screw, whose end is in contact with the liquid crystal panel support member, and means for rotating the set-screw. Also, the resilient members should preferably form a parallelogrammic link. Further, the resilient members and the liquid crystal panel support member may be combined into an integral body.
With the liquid crystal pixel interpolating mechanism in a liquid crystal photo printer in accordance with the present invention, the liquid crystal panel support member is supported with the resilient members, and the pushing means is provided for pushing the liquid crystal panel support member. Therefore, when the liquid crystal panel support member is merely pushed by the pushing means, the resilient members become deflected, and the liquid crystal panel can be displaced. Accordingly, after the image displayed on the liquid crystal panel, which is located at a reference position, has been projected onto the photosensitive material and the photosensitive material is thus exposed image-wise, the liquid crystal panel support member is pushed by the pushing means, and the liquid crystal panel is thereby displaced from the reference position. At the position to which the liquid crystal panel has thus been displaced, the exposure operation is performed again. In this manner, a pixel shifting operation can be performed easily by the utilization of the simple and cheap mechanism.
In such cases, the distance of axial advance of the end of the set-screw is markedly short with respect to the rotation angle of the set-screw and is in proportion to the rotation angle of the set-screw. Therefore, with the liquid crystal pixel interpolating mechanism in a liquid crystal photo printer in accordance with the present invention, wherein the set-screw is employed in the pushing means, the distance of displacement of the liquid crystal panel can be set accurately.
Also, with the liquid crystal pixel interpolating mechanism in a liquid crystal photo printer in accordance with the present invention, wherein the resilient members form a parallelogrammic link, the liquid crystal panel can be translated in parallel from the reference position without being rotated. Therefore, the desired pixel shifting operation can be performed accurately.
Further, in cases where the resilient members and the liquid crystal panel support member are is formed as an integral body from, for example, a plastic material, the constitution for supporting the liquid crystal panel can be formed at a low cost and easily.